小兴凯湖浮游植物功能群特征及其影响因子

为分析北方寒冷地区浑浊型富营养化湖泊湿地浮游植物功能群时空变化特征及其影响因子,分别于2014年春季(5月)、夏季(7月)和秋季(9月)对小兴凯湖12个采样点进行了浮游植物采样,系统分析了浮游植物功能群的组成特征. 结果表明:小兴凯湖浮游植物共划分为21个功能群,其中重要功能群为H1、MP、D、C、Y、X2、J和W1,春季以功能群X2和D占优势,分别占49.02%和24.32%；夏季以功能群X2、C和H1占优势,分别占28.86%、16.11%和14.16%；秋季以功能群X2和C占优势,分别占46.97%和27.66%. 浮游植物功能群随季节变化表现为X2+D→X2+C+H1→X2+C的特点,反映至水体环境,春季为低温、高营养、中度浑浊水体,夏季为高温、富营养、高度浑浊、低光照水体,秋季为低温、富营养、高度浑浊、低光照水体. Pearson线性相关性分析表明,重要功能群功能群H1同ρ(TP)极显著正相关；功能群D同透明度、ρ(BOD₅)极显著正相关,同ρ(COD_Cr)显著正相关,同浊度和ρ(TIC)显著负相关；功能群X2同透明度极显著正相关,同ρ(TP)显著正相关,同浊度极显著负相关. RDA多元统计分析表明,ρ(TP)、浊度、透明度是小兴凯湖浮游植物功能群的主要影响因子,ρ(TC)、ρ(TOC)同大多数小兴凯湖浮游植物功能群正相关,但不是主要影响因子,ρ(TIC)与小兴凯湖浮游植物功能群无相关性. 小兴凯湖虽然整体营养盐水平很高,但较高的浊度抑制了浮游植物的生长. 

Characteristics and Physical Factors of Phytoplankton Functional Groups in Small Xingkai Lake

In order to investigate the characteristics and impact factors of special and seasonal dynamics of phytoplankton functional groups in a turbid eutrophic lake wetland in a cold northern region, we collected samples at 12 sites in Small Xingkai Lake in spring (May), summer (July), and autumn (September) in 2014, and systematically analyzed the composition characteristics of the phytoplankton functional groups. The results showed that there were 21 functional groups in Small Xingkai Lake, and the dominant groups included functional groups H1, MP, D, C, Y, X2, J and W1. The dominant groups were X2 (49.02%) and D (24.32%) in spring associated with low temperature, high-trophic and turbid water; they were X2 (28.86%), C (16.11%) and H1 (14.16%) in summer associated with high temperature, eutrophic, high turbidity and low illumination; and they were X2 (46.97%) and C (27.66%) in autumn associated with low temperature, eutrophic, high turbidity and low illumination water. Pearson analysis suggested that group H1 was significantly positively related with total phosphorus (TP); group D was significantly positively related with Secchi depth (SD), biological oxygen demand (BOD₅), and chemical oxygen demand (COD_Cr), and significantly negatively related with TURBID and total inorganic carbon (TIC). Group X2 was significantly positively related with SD and TP, and significantly negatively related with turbidity. RDA analysis revealed that TP, turbidity and SD were the main impact factors on the phytoplankton functional groups composition and distribution in Small Xingkai Lake. TP and SD were positively related with most of the phytoplankton functional groups, but not main the impact factors. However, there was no significant relationship between IC and phytoplankton functional groups. Overall, the turbidity inhibited the growth of phytoplankton, although the nutrient level was high in Small Xingkai Lake.